A brochure from the Siemens company entitled “MAMMOMAT 3000 Nova” shows an X-ray diagnostic unit for mammography examinations. The attachment unit mentioned in the introduction may be a biopsy unit, as shown in the brochure, for taking tissue samples from a breast, or else a magnification table as shown in the brochure from the KRAMEX company entitled “AVIVA The Mammography System Designed to Grow with Technology”.
Used in conjunction with magnification i.e. when a magnification table is attached to an object table or to an image receptor, the table surface of the magnification attachment unit happens to lie at a distance from the image receptor. When taking an X-ray photograph of a breast, the X-ray grid mentioned in the introduction is normally used to reduce the stray X-ray radiation which causes a detectable deterioration in the image quality. When magnification is used, however, an X-ray grid is not used. This is because, with a magnification table attached, the stray radiation does not cause a degradation in the image quality when taking a photograph, owing to the space created between the table surface of the magnification table and the image receptor. An X-ray grid is also not used for a biopsy examination because in this case just a small section of the breast is irradiated.
If an operator forgets to move the X-ray grid out of the X-ray field when using magnification or when performing a biopsy examination, an unnecessarily high X-ray dose can accidentally be given to the breast to be examined in order to obtain a good image quality, because the X-ray grid absorbs a large proportion of the X-ray dose.